Drug Dependence, a Chronic Medical Illness
Treatment, Insurance, and Outcomes Evaluation
A. Thomas McLellan, PhD; David C. Lewis, MD; Charles P. O'Brien,
MD, PhD; Herbert D. Kleber, MD
The effects of drug dependence on social systems has helped shape the generally held view that drug dependence is primarily a social problem, not a
health problem. In turn, medical approaches to prevention and treatment are lacking. We examined evidence that drug (including alcohol) dependence is a chronic medical illness. A literature review compared the
diagnoses, heritability, etiology (genetic and environmental factors), pathophysiology, and response to treatments (adherence and relapse) of drug dependence vs type 2 diabetes mellitus, hypertension, and asthma.
Genetic heritability, personal choice, and environmental factors are comparably involved in the etiology and course of all of these disorders. Drug dependence produces significant and lasting changes in brain
chemistry and function. Effective medications are available for treating nicotine, alcohol, and opiate dependence but not stimulant or marijuana dependence. Medication adherence and relapse rates are similar across
these illnesses. Drug dependence generally has been treated as if it were an acute illness. Review results suggest that long-term care strategies of medication management and continued monitoring produce lasting
benefits. Drug dependence should be insured, treated, and evaluated like other chronic illnesses.